Tbx2 Controls Lung Growth by Direct Repression of the Cell Cycle Inhibitor Genes Cdkn1a and Cdkn1b
Figure 8
Prolonged expression of TBX2 maintains proliferation of mesenchymal progenitor cells in the adult lung.
Analysis of wildtype and Tbx2cre/+;HprtTBX2/+ mice at P40. (A) Morphology of P40 mice and lungs. (B) Statistical analysis of relative lung per body weight; spleen was analyzed as a control organ. Increase of the lung weight in Tbx2cre/+;HprtTBX2/+ mice was statistically significant (*). (C) Immunofluorescence analysis of GFP and Tbx2/TBX2 expression, histological analysis by haematoxylin and eosin (HE) and Masson's staining on sections of P40 lungs. (D) BrdU incorporation assay of frontal sections of the lung. TBX2-overexpressing mice show highly increased BrdU incorporation. (E) Analysis of apoptosis by TUNEL staining. (F) Immunofluorescence analysis of Fn1, Postn, S100a4, Cdkn1a and Cdkn1b expression on lung sections at P40. Genotypes are as indicated. Scale bars in A represent 1 cm and 2.5 mm, respectively. Scale bars in C represent 100 µm for GFP, otherwise 50 µm, in D 50 µm, in E 100 µm, in F 100 µm for Fn1 and Postn and for all others 50 µm. For statistics see Table S1F. (G) Model of the role of Tbx2 in lung development.